Fixes false leaks on thread retval.
Reviewed By: thurston
Differential Revision: https://reviews.llvm.org/D150106
static thread_return_t THREAD_CALLING_CONV asan_thread_start(void *arg) {
AsanThread *t = (AsanThread *)arg;
SetCurrentThread(t);
- return t->ThreadStart(GetTid());
+ auto self = GetThreadSelf();
+ auto args = asanThreadArgRetval().GetArgs(self);
+ thread_return_t retval = t->ThreadStart(GetTid());
+ asanThreadArgRetval().Finish(self, retval);
+ CHECK_EQ(args.arg_retval, t->get_arg());
+ return retval;
}
-INTERCEPTOR(int, pthread_create, void *thread,
- void *attr, void *(*start_routine)(void*), void *arg) {
+INTERCEPTOR(int, pthread_create, void *thread, void *attr,
+ void *(*start_routine)(void *), void *arg) {
EnsureMainThreadIDIsCorrect();
// Strict init-order checking is thread-hostile.
if (flags()->strict_init_order)
// stored by pthread for future reuse even after thread destruction, and
// the linked list it's stored in doesn't even hold valid pointers to the
// objects, the latter are calculated by obscure pointer arithmetic.
-#if CAN_SANITIZE_LEAKS
+# if CAN_SANITIZE_LEAKS
__lsan::ScopedInterceptorDisabler disabler;
-#endif
- result = REAL(pthread_create)(thread, attr, asan_thread_start, t);
+# endif
+ asanThreadArgRetval().Create(detached, {start_routine, arg}, [&]() -> uptr {
+ result = REAL(pthread_create)(thread, attr, asan_thread_start, t);
+ return result ? 0 : *(uptr *)(thread);
+ });
}
if (result != 0) {
// If the thread didn't start delete the AsanThread to avoid leaking it.
}
INTERCEPTOR(int, pthread_join, void *thread, void **retval) {
- return REAL(pthread_join)(thread, retval);
+ int result;
+ asanThreadArgRetval().Join((uptr)thread, [&]() {
+ result = REAL(pthread_join)(thread, retval);
+ return !result;
+ });
+ return result;
}
INTERCEPTOR(int, pthread_detach, void *thread) {
- return REAL(pthread_detach)(thread);
+ int result;
+ asanThreadArgRetval().Detach((uptr)thread, [&](){
+ result = REAL(pthread_detach)(thread);
+ return !result;
+ });
+ return result;
}
INTERCEPTOR(int, pthread_exit, void *retval) {
+ asanThreadArgRetval().Finish(GetThreadSelf(), retval);
return REAL(pthread_exit)(retval);
}
# if ASAN_INTERCEPT_TRYJOIN
INTERCEPTOR(int, pthread_tryjoin_np, void *thread, void **ret) {
- return REAL(pthread_tryjoin_np)(thread, ret);
+ int result;
+ asanThreadArgRetval().Join((uptr)thread, [&]() {
+ result = REAL(pthread_tryjoin_np)(thread, ret);
+ return !result;
+ });
+ return result;
}
# endif
# if ASAN_INTERCEPT_TIMEDJOIN
INTERCEPTOR(int, pthread_timedjoin_np, void *thread, void **ret,
const struct timespec *abstime) {
- return REAL(pthread_timedjoin_np)(thread, ret, abstime);
+ int result;
+ asanThreadArgRetval().Join((uptr)thread, [&]() {
+ result = REAL(pthread_timedjoin_np)(thread, ret, abstime);
+ return !result;
+ });
+ return result;
}
# endif
}
static ThreadRegistry *asan_thread_registry;
+static ThreadArgRetval *thread_data;
+
static Mutex mu_for_thread_context;
static LowLevelAllocator allocator_for_thread_context;
// MIPS requires aligned address
static ALIGNED(alignof(
ThreadRegistry)) char thread_registry_placeholder[sizeof(ThreadRegistry)];
+ static ALIGNED(alignof(
+ ThreadArgRetval)) char thread_data_placeholder[sizeof(ThreadArgRetval)];
asan_thread_registry =
new (thread_registry_placeholder) ThreadRegistry(GetAsanThreadContext);
+ thread_data = new (thread_data_placeholder) ThreadArgRetval();
initialized = true;
}
return *asan_thread_registry;
}
+ThreadArgRetval &asanThreadArgRetval() {
+ InitThreads();
+ return *thread_data;
+}
+
AsanThreadContext *GetThreadContextByTidLocked(u32 tid) {
return static_cast<AsanThreadContext *>(
asanThreadRegistry().GetThreadLocked(tid));
// --- Implementation of LSan-specific functions --- {{{1
namespace __lsan {
-void LockThreadRegistry() { __asan::asanThreadRegistry().Lock(); }
+void LockThreadRegistry() {
+ __asan::asanThreadRegistry().Lock();
+ __asan::asanThreadArgRetval().Lock();
+}
-void UnlockThreadRegistry() { __asan::asanThreadRegistry().Unlock(); }
+void UnlockThreadRegistry() {
+ __asan::asanThreadArgRetval().Unlock();
+ __asan::asanThreadRegistry().Unlock();
+}
static ThreadRegistry *GetAsanThreadRegistryLocked() {
__asan::asanThreadRegistry().CheckLocked();
}
void GetAdditionalThreadContextPtrsLocked(InternalMmapVector<uptr> *ptrs) {
- GetAsanThreadRegistryLocked()->RunCallbackForEachThreadLocked(
- [](ThreadContextBase *tctx, void *ptrs) {
- // Look for the arg pointer of threads that have been created or are
- // running. This is necessary to prevent false positive leaks due to the
- // AsanThread holding the only live reference to a heap object. This
- // can happen because the `pthread_create()` interceptor doesn't wait
- // for the child thread to start before returning and thus loosing the
- // the only live reference to the heap object on the stack.
-
- __asan::AsanThreadContext *atctx =
- static_cast<__asan::AsanThreadContext *>(tctx);
-
- // Note ThreadStatusRunning is required because there is a small window
- // where the thread status switches to `ThreadStatusRunning` but the
- // `arg` pointer still isn't on the stack yet.
- if (atctx->status != ThreadStatusCreated &&
- atctx->status != ThreadStatusRunning)
- return;
-
- uptr thread_arg = reinterpret_cast<uptr>(atctx->thread->get_arg());
- if (!thread_arg)
- return;
-
- auto ptrsVec = reinterpret_cast<InternalMmapVector<uptr> *>(ptrs);
- ptrsVec->push_back(thread_arg);
- },
- ptrs);
+ __asan::asanThreadArgRetval().GetAllPtrsLocked(ptrs);
}
void GetRunningThreadsLocked(InternalMmapVector<tid_t> *threads) {
#include "asan_stats.h"
#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_libc.h"
+#include "sanitizer_common/sanitizer_thread_arg_retval.h"
#include "sanitizer_common/sanitizer_thread_registry.h"
namespace __sanitizer {
// Returns a single instance of registry.
ThreadRegistry &asanThreadRegistry();
+ThreadArgRetval &asanThreadArgRetval();
// Must be called under ThreadRegistryLock.
AsanThreadContext *GetThreadContextByTidLocked(u32 tid);
CHECK(t);
CHECK(!t->second.detached);
if (t->second.done) {
- // Detached thread has no use after it started and returned args.
+ // We can't retrive retval after detached thread finished.
data_.erase(t);
return;
}
template <typename JoinFn /* returns true on success */>
void Join(uptr thread, const JoinFn& fn) {
// Remember internal id of the thread to prevent re-use of the thread
- // between fn() and DetachLocked() calls. We can't just lock JoinFn
- // like in Detach() implementation.
+ // between fn() and AfterJoin() calls. Locking JoinFn, like in
+ // Detach(), implementation can cause deadlock.
auto gen = BeforeJoin(thread);
if (fn())
AfterJoin(thread, gen);
// RUN: %run not %t 10 0 0 1 2>&1 | FileCheck %s --check-prefixes=LEAK,LEAK234
// FIXME: Remove "not". There is no leak.
-// False LEAK234 is broken for ASAN, LSAN.
-// RUN: %run %if asan %{ not %} %if lsan-standalone %{ not %} %t 10 0 0 0
+// False LEAK234 is broken for LSAN.
+// RUN: %run %if lsan-standalone %{ not %} %t 10 0 0 0
#include <pthread.h>
#include <stdlib.h>